This invention relates generally to multi-section toolbars drawn by a tractor such as used in agriculture and is more particularly directed to a bi-fold hinge and control system therefor for use in a folding toolbar.
Multi-section toolbars of the prior art generally include first and second wings pivotally mounted to a main, or center, frame. The wings or "bars" are pivotable between a use position in which the wings are oriented generally horizontally and extend laterally with respect to the main frame and transverse to the direction of travel of the vehicle which draws the toolbar, and a transport or storage position in which the wings extend either rearwardly of the main frame and parallel to the direction of travel of the vehicle or are folded upward so that the width of the entire retracted mechanism is no longer than the length of the main frame. Each of the toolbar wings is coupled to the main frame of the toolbar by means of a hinge mechanism which is aligned either vertically or horizontally to allow the wing to pivot in either one or the other of these directions. Pivoting displacement of the wing sections is generally accomplished by means of the tractor's hydraulic system which is manually controlled by the operator of the vehicle.
With increasing tillage implement size and pulling vehicle power, toolbar length have correspondingly increased. In addition, the numbers and combinations of agricultural tools such as planters, cultivators, fertilizer applicators, etc., arranged in tandem and drawn by the tractor have increased with increasing tractor power. For example, a forward toolbar may be provided with disc gangs to chew up heavy layers of stalks or stubble. These implements may be followed by two or more trailing toolbars upon which may be mounted in tandem various combinations of ridging implements, plow tips, rotary hoes, etc. Where the leading multi-section toolbar is rigidly mounted to an aft portion of the tractor and the trailing toolbars are pivotally coupled to the tractor and are closely positioned aft of the leading toolbar, the maneuverability of the tractor may be restricted. For example, tight turns may be precluded by interference between the leading toolbar and the immediately trailing toolbar or implements mounted thereto. Interference between adjacent toolbars may be avoided by increasing the length of the tongue assembly of the trailing frame, however, the increased length of the overall field cultivator or planter arrangement also restricts the maneuverability of the tractor.
The present invention is intended to solve the aforementioned problems of prior art field cultivators or planters by providing a bi-fold hinge for a folding toolbar which allows the toolbar wings to pivot either vertically upward in a nonuse or storage position or in a forward direction to provide separation between the toolbar wings and closely spaced, trailing implements. The bi-fold hinges positioned on respective ends of a center section of a three-point tractor mounted toolbar allow for automatic forward pivoting displacement of a toolbar wing when the tractor is turned so as to preclude interference between the toolbar wing and trailing implements.